The invention relates to a micro-fluidic system with mutually similar fluid paths arranged in parallel with one another.
For chemical or biochemical analysis and synthesis processes, micro-fluidic systems promise vast improvements over macroscopic systems with respect to quality, speed and cost, because the reaction times and dwell times within the fluid paths are very short, only very small amounts of a substance are used, and these substances are processed very precisely and reproducibly. To satisfy the requirements regarding quantity, throughput and productivity, particularly in industrial applications, a possibly very large number of fluid paths must be connected in parallel (numbering up). Depending on the application, this parallel connection can be implemented by forming and parallel-connecting a plurality of similar micro-channels in micro-fluidic components, e.g., a mixer, or by multiply parallel-connecting entire micro-fluidic components or systems assembled from micro-fluidic components. With suitable micro-technology processes (e.g., etching processes, LIGA techniques or micro-mechanics) the parallel fluid paths can be produced in the same manner with great precision, such that the same process conditions, e.g., pressure, temperature, mass rate of flow, etc., are present in all the parallel-connected fluid paths. As a result, the same products can be obtained from all the parallel fluid paths and can be combined without any loss of quality.
However, micro-fluidic systems are subject to operational changes in the effective flow resistance due to both local fluctuations in the viscosity of the fluid and obstructions in the fluid paths, which can further change the operating conditions and cause progressive obstruction, resulting eventually in complete failure of the system. Whereas in macroscopic systems the mass flow rate, for example, can be readily measured with practically no interference and supplied to a flow control, the same cannot be achieved for the individual paths in parallelized micro-fluidic systems at a justifiable cost.